1. Field of the Invention
The present invention relates to surveillance camera systems, and more particularly to an environmentally sealed enclosure for a surveillance camera for outdoor use.
2. Description of the Prior Art
The use of surveillance cameras and related systems is becoming increasingly more prevalent. Not only are surveillance cameras used in such traditional institutions as banks and casinos, but their use has spread to retail and business establishments, indoor and outdoor entry points, airport security checkpoints, government buildings, parking lots, and the like.
In the field of surveillance cameras, it is often necessary for a surveillance camera to be mounted in a housing that is located in a remote or outdoor location (such as the top of a pole, on a ledge, on the side of a wall, the underside of an eave, etc.) where it is exposed to wide variations in temperature, pressure and humidity. Changes in pressure and humidity can be particularly harmful to the delicate internal electronics and camera optics of surveillance camera systems, and that may impair, damage or shorten the life of these components. Some indoor environments may also be hazardous to the camera and internal electronics, such as a foundry or factory where toxic gasses, dust and/or debris are present in the air.
Many existing camera housing enclosures include fans and/or heaters to help control the interior environment, but they are not sealed. As a result, such enclosures do not provide adequate protection to the camera inside, and cannot be used in harsh or extreme climactic conditions such as those where there is considerable precipitation, humidity, ice or other moisture, where the temperature is very hot or very cold, and/or where there are wide variations in temperature.
Other existing camera housings are sealed in order to prevent moisture and debris from entering the enclosure. However, because of the way existing sealed camera enclosures are manufactured and assembled, failures in the seals may occur after a relatively short period of time particularly in harsh environments such as those described above. A typical elongated surveillance camera housing may include a one or two-part lower housing, a front wall, a rear wall, and an upper housing or lid. Each of these housing parts is ordinarily made of a rigid material such as metal or plastic. A viewing panel is usually provided in the front wall. Thus, a first seal is needed around the front viewing panel where it attaches to the front wall. Another longitudinal seal (or two) is needed between the upper and lower housing parts when they are coupled together. A third seal is needed around the front wall where it engages the front end of the coupled housing, and a fourth seal is needed around the rear wall where it engages the back end of the coupled housing. Such enclosures have numerous potential failure points where the integrity of a seal may be lost. These include any uneven or poorly constructed surfaces of any housing part that is to be sealed against another housing part, joints or poorly mated surfaces on or along such housing parts, and/or junctions where one seal engages against another seal (such as where a longitudinal seal between upper and lower housing parts abuts the seal for the front or back wall of the enclosure). A seal failure at any of these points will compromise the integrity of the enclosure, and expose the electronics and camera inside to moisture, debris and/or other environmental elements that may impair, damage or shorten the life of these components.
Adhesives may be used to adhere a sealing structure to a housing part, but are generally disfavored for many reasons. In some cases, adhesives may wear out or fail more readily than the sealing structure to which they are adhered. The adhesive may not bond correctly, or the wrong adhesive may be used, which can actually accelerate a seal failure. Moreover, if a sealing structure must be replaced, remnants of any adhesive used must be removed from the housing part before a new sealing structure is installed. Otherwise, these remnants may become potential failure points for the new seal. For these reasons and others, adhesives generally do not provide the necessary reliability for sealing outdoor surveillance camera enclosures.
It is therefore desirable to provide a sealed surveillance camera housing having a minimal number of potential failure points along any sealed surfaces to provide protection for the internal electrical and mechanical components from exposure to precipitation, moisture and other external foreign contaminants. It is also desirable to provide improved and reliable sealing structures for such camera housings. It is also desirable to provide camera housing sealing structures that do not rely on adhesives.